Targeted Therapy

Targeted therapies are treatments for cancer that directly affect cancer cell growth. Targeted therapy is different from chemotherapy in that chemotherapy affects all rapidly dividing cells, including some healthy cells. On the other hand, targeted therapies disrupt cancer growth by blocking activities in the cell that help tumor growth. Targeted therapies may be given alone or in combination with current chemotherapy treatments.

What are some targeted therapies used in breast cancer?

Currently there are many classes of targeted therapies used in a variety of cancer types. Common targeted therapies used in breast cancer include Herceptin®, Avastin®, and Tykerb®.

Trastuzumab (Herceptin®)
Herceptin® is used to treat breast cancer tumors that have too much HER-2 (human epidermal growth factor receptor 2) protein. Breast cancers that have too much HER-2 usually grow and spread quickly. Herceptin® is an antibody that blocks the HER-2 protein on breast cancer cells and slows cancer cell growth.

Bevacizumab (Avastin®)
Avastin is an antibody that works by preventing new blood vessel growth to tumors, therby starving the tumor of its nutrient and oxygen supply.

Lapatinib (Tykerb®)
Tykerb® is used to treat advanced or metastatic breast cancer that is HER-2 positive either alone or in combination with chemotherapy. Tykerb® is typically used in patients who have already tried other breast cancer therapies.

Specific Drug information

More in-depth information on the drugs used in targeted therapy for breast cancer follows:

Trastuzumab (Herceptin® HER2/neu antibody)

How does this drug work?

Herceptin® is an antibody drug that binds the HER2/neu protein, a substance on some cancer cells that can help cancer cells grow abnormally. About one-fifth of all women with breast cancer have tumors that make HER2/neu. Herceptin® is given by vein every week or every 3 weeks either alone or with chemotherapy.

Common side effects

Herceptin® is usually well tolerated Less common side effects with your type of chemotherapy:

Chills, fever

Nausea, vomiting

Chest pain

As with any drug, other side effects that were not mentioned may occur.

General concerns

Report vomiting or severe nausea lasting more than 1 day.

Immediately report any fevers of 101° F or higher, with or without chills.

Ask your doctor about a birth control method for you

Report any symptoms which are unusual for you.

Bevacizumab (Avastin®)

How does this drug work?

Avastin® is an anti-VEGF (vascular endothelial growth factor) antibody drug that binds to VEGF causing decreased blood supply to cancer cells and prevents cancer cells from growing. Avastin? is given by vein every 1-3 weeks either alone or with chemotherapy.

Common side effects

Increased blood pressure

Increased protein in urine

Slows wound healing

Less common side effects with your type of chemotherap:

Constipation

Nausea/vomiting (rare)

Headache

Nose bleeds

As with any drug, other side effects that were not mentioned may occur.

General concerns

Report nose bleeds, gum bleeds, or any unusual bleeding or bruising

If you have a fever of 101° F (38.3° C) with or without chills, or chills alone, call the nurse immediately. If you cannot reach the nurse or on-call doctor (after hours), go to an emergency room.

Ask your doctor about a birth control method for you.

Report any symptoms which are unusual for you.

Lapatinib (Tykerb®)

How does this drug work?

Tykerb® is an oral antibody drug that binds the HER2/neu protein, a substance on some cancer cells that can help cancer cells grow abnormally. Tykerb® is given orally once daily, either alone or with capecitabine (Xeloda®).

Common side effects

Lowers number of white blood cells (which fight against infection), red blood cells (which carry oxygen and help against feeling tired), and platelets (which cause blood to clot). A low number of these cells may lead to infection, anemia, and bleeding.

Diarrhea

Nausea

Rash

Hand-foot reaction: skin on palms of hands or soles of feet may be dry, cracked, red, numb, painful or swollen.

Less common side effects with your type of chemotherapy

Fatigue

Mouth sores

Loss of appetite

As with any drug, other side effects that were not mentioned may occur.

General concerns

Report nausea or vomiting that is not relieved by anti-nausea medication

Immediately report any fevers of 101° F or higher, with or without chills

Report nose bleeds, gum bleeds, or any unusual bruising

Report moderate to severe diarrhea

Report hand-foot reactions

Ask your doctor about a birth control method for you

Report any symptoms which are unusual for you

Other concerns with your type of chemotherapy

To prevent hand-foot reaction, do not wear tight fitting shoes or perform activities that may place pressure on your hands or feet. You may also use creams on your hands and feet.

There may be drug interactions between Tykerb® and some antibiotics and other medications. It is important that you tell your doctor all medications that you are currently taking before you start Tykerb®.

To Report Your Concerns

You may contact the Breast Care Center at 415-353-7070. During clinic hours Monday through Friday, the triage nurse will return your call. After 5 p.m. or on weekends, an on-call doctor will return your call.